# Chameau (HBO1) regulates starvation resistance in Drosophila melanogaster in a temperature-dependent manner

## TL;DR

This study shows that a gene called Chameau (HBO1) helps fruit flies survive without food, but only at cooler temperatures, and not when it's warmer.

## Contribution

The study reveals a temperature-dependent role of Chameau in regulating starvation resistance in fruit flies.

## Key findings

- Chameau promotes starvation resilience at 23°C but is bypassed at higher temperatures.
- Increased temperature rescues gene expression and metabolic defects in chm mutants.
- Citrate supplementation improves starvation resilience in chm mutants at lower temperatures.

## Abstract

Chameau (HBO1) gene function in starvation resistance is bypassed by slightly elevated temperatures in Drosophila, suggesting a temperature-dependent metabolic role.

The body temperature of Drosophila melanogaster depends on the extrinsic temperature. Numerous studies show that environmental temperature influences metabolism, lifespan, and starvation resilience. We have previously shown that Chameau (Chm), a MYST-domain acetyltransferase, promotes aging but also increases starvation resilience. Strikingly, the metabolic increase associated with a 2°C temperature rise was sufficient to bypass the requirement for Chm in starvation resilience, suggesting that Chm modulates metabolism in a temperature-dependent manner. The increase in temperature also rescued the dampened expression of genes involved in starvation response, the weight loss, and the misregulation of trehalose, which we observed in chm mutants at 23°C. Thus, Chm regulates starvation at ≤23°C but becomes obsolete at higher temperatures, likely because of efficient acetyl-CoA generation ensuring similar acetylation despite lower Chm. Supporting this, citrate supplementation increased starvation resilience of chm mutants at lower temperatures. Our finding that a gene’s role manifests only under specific environments has important implications in light of global climate change.